Negative holder for photographic printing machines



gw. 'c. HUEBNER NEGATIVE HOLDER FOR PHOT OGRAPHIC PRINTING MACHINES -0rigina1 Filed July 27, 1928 4 Sheets-Sheet -1 Aug. 2, 1932. v w. c. HUE'BNER NEGATIVE HOLDER FOR PHOTOGRAPHI G PRINTING MACHINES 4 Sheets-Sheet 2 Original Filed July 27, 1928 Y M M m m W5 5 Aug. 2, 1932. w. c. HUEBNER 1,870,008

NEGATIVE HOLDER FOR PHOTOGRAP'HIC PRINTING MACHINES Original Filed July 27, 1928 4 Sheets-Sheet 4 a e a A ma 4.2.2:

172 7167110? 2 Z Zia/m C WUGZWYFZ B1 9 Patented Aug. 2, I932 UNITED STATES'PATENT OFFICE WILLIAM C. HUEBNER, CHICAGO, ILLINOIS, ASSIGNOR TO HU'EBNER-BLEISTEIN PATENTS COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF YORK NEGATIVE HOLDER FOR PHOTOGRAPHIC PRINTING MACHINES Application filed July 27, 1928, Serial No. 295,683.

This invention relates to improvements in negative holders for photographic printing machines.

In the art of making press plates photographically on machines commonly called photo-composers or photographic printingmachines, it is the general practice to fasten the negative to a holder or frame which is then attached to a movable carriage of the machine proper. In making the photographic impressions, great pressure is required betweenthe negative and thesensitized or press plate in order to obtain accurate prints and heretofore this pressure has been I system for obtaining obtained either by mechanical pressureapplying means or by vacuum, that is, by

exhausting the air from between the negative and press plate.

In those machines employing the vacuum pressure, considerable difficulty has heretofore been experienced in providing a complete air sealing means be I tween the several parts necessary to obtain the vacuum between the negative and press plate. The most common form of negative used is, of course, the glass negative plate and so far as I am aware, no means have heretofore been provided by which a vacuum seal could be obtained where a flexible film negative is employed, which flexible films are now coming into use.

One object of my invention is to provide an improved negative holder of the type above referred'to which is adapted for either glass or flexible film negatives and wherein a complete air seal is obtainable between the several parts constituting the. negativecarrying structure on the one hand and the press plate on the other hand, whereby to obtain the intimate pressure contact between the negative and press plate during exposure.

Another object of my invention is to providea negative holder of the character indicated wherein the air sealing means are so mounted and disposed on the negativecarrying frames or holders that, when as seinbleththerc is no danger of any of the parts becoming loose or disengaged, to the end that such negative holders may be employed in either horizontal, vertical, or other of said two pensate for negatives of different thicknesses Renewed January 6, .1932.

position on the machine, thereby permitting adjustments of the negative holder from operative to inoperative position and facilitating the operation and minimizing labor.

Another object of my invention is to provide negative holding means which comprise,

essentially, a main holder and a negative holder proper such that the relative levels holders may be varied to comin combination with air sealing means between the two holders, which will automatically maintain the seal in any relative adjusted levels of the two holders.

Another object'of my invention is to provide a negative holder and means associated therewith so arranged as to eliminate or minimize the possibility of the press plate being drawn into any gaps when the vacuum is on to thereby preserve the flat surface contour of the press plate during exposure and prevent distortion of the images printed thereon.

Other objects of the invention will more clearly appear from the description and claims hereinafter following. 1

In the drawings forming a part of this specification, Figure 1 is a plan view of an improved negative holder embodying my so improvements, part-of the glass negative being broken away to illustrate certain under lying features. Figure 2 isa broken vertical sectional view. corresponding substantially to the line 2-2 of Figure 1, Figure 2 being on an enlarged scale. Figure 3 is a similar vertical sectional view broken away and corresponding substantially to the line 33 of Figure 1. Figure 4 is a broken view similar to Figure 2, illustrating the holder as used with a glass negative of lesser thickness than the one illustrated in Figure 2. Figure 5 is a plan view'of the negative holder proper, detached. Figure 6 is a transverse sectional view. of the holder proper shown in Figure 5 and corresponding to the line 6.-6 thereof, parts being broken away to accommodate the figure on the sheet. -Figure 7 is a plan view of the guide or gap frame detached. Figure 8 is an end view of the frame shown in Figure 7 Figure 9 is a view similar to Figure 1, showing the improved holder as adapted for the holding of a flexible film negative. Figure is a sectional view of the construction illustrated in Figure 9 and corresponding to the line 10-10 thereof and on a larger scale. Figure 11 is a detail plan view of the auxiliary frame utilized in holding a flexible film negative and illustrating more particularly one of the clamping and stretching jaws. Figure 12 is a view similar to Figure 1, illustrating a somewhat different embodiment of the invention. And Figure 13 is an enlarged sectional view of the holder shown in Figure 12, corresponding to the line 13--13 thereof.

Referring first to the construction in Figures 1 to 8, inclusive, the improved negative holder comprises, broadly, a main or outer holder or frame A; a negative holder proper or negative frame proper B; and a guide or gap frame The-main holder A, as shown, is of rectangular form andconsists of a main heavy plate having a rectangular central opening 21 to permit transmission of the light rays therethrough. Around all edges of the plate 20 is provided a sealing arrangement which preferably consists of"a strip 22 of against the usual press plate.

' arisin two sets of throughan angle of 90 generally come inthis shape.

is provided with a plurality sponge rubber'held in place by a channellike arrangement consisting ofa bottom plate 23 and side plates 2%:24, as shown in Figure 2. The rubber strip will be compressed along'its bottom half by the plates 24 when the strip is secured in place so that the strip has, normally, a widened top section as shown, and'which is adapted to yield and spread slightly when the holder is applied The main holder A is adapted to be mounted on the photographic printing machine in a definite predetermined position and location, for which any suitable means may be provided, the one which is illustrated comdowel holes 25-25 and 26-26, the former being on one edge and the latter along an edge at right angles thereto, whereby the holder may be turned with reference to the carnage or other part of the photographic printing machine, to which it 'is attached.

The negative rectangular outline, since glass negatives B preferably comprises a rigid plate of steel or other suitable material of rectangular cross section, thus providing a flat bottomsurface 27, a flat top surface 28 and a Vertical flat surface 29 defining the usual rectangular opening therein to permit the passage of the light rays.

. In order to properly secure the glass nega tive D on the holder proper B, the latter of adjustable clamps around its periphery, there being six directly holder proper B isals'o of Said holder shown, two each on the long sides and one each on the narrower sides of the frame. Each of said clamps preferably comprises a block 30 from which are extended inwardly two spaced guide pins corresponding holes in the plate and hence maintain the block 30 parallel with the corresponding side of the holder 13. Secured to the top of each block 30 is aclamp plate proper 32, preferably edge 33 adapting it to engage the corresponding beveled edge of the glass negative (which are customarily so finished). It will be noted from inspection of Figures 2 and 6 that the clamp plates proper 32 are of lesser thickness than the glass negatives so as to positively insure the printing surface of the negative being above the clamps and hence avoiding any possibility of mar-ring the sensitized press plate during exposure. Each clamp is adjusted inwardly and outwardly by'a headed screw 34 threaded into the holder plate so that the clamping jaws will be moved inwardly and outwardly, as is clear from the drawings.

Preferably, the holder proper B is recessed as indicated at 35-455 opposite each clamp so asto reduce the over-all dimensions of the holder, as will be understood.

In order to positively insure an air seal between the negative and the holder proper B when the negative is in place, the holder B is supplied with a thin layer 36 of rubber or suitable material on its upper flat surface 28, and it will be obvious that, as the beveled edge clamps secure the negative in place, there is a slight squeezing of the rubber layer 36. In order that the negative holder proper B may be placed and retained in predetermined position and location on the main holder A, the holder 13 is preferably pro vided with dowel hole bushings 37'on opposite sides thereof, with which cooperate corresponding dowelsonthe main holder A.

To hold the holder proper B firmly assembled with the main holder A after the two relative levels of the two holders, I employ the following means, best illustrated in Figure 2. At each corner of the main frame A, is alevel-adjusting screw 38 having a suitable knurled head 39 by which the spacing between the two holders may be adjusted, as will be obvious. proper level of the holder B with reference adjustment of the to the holder Ahas been obtained, the parts are then locked by four other screws 40, one at each corner, which screws 40 pass freely through the plate 20 of the main holder and have threaded engagement with the holder B. Each screw 40 is also preferably provided with a knurled head 41 to facilitate adjustment thereof. By comparing Figures 2 and 4, it will be noted that the holderB in the latter figure is elevated an appreciable 31 which work in having a beveled inner I When the r distance, as compared with its location in either one of the vacuum heads 5151, two Figure 2, in order to bring the level of the being illustrated, when on a narrow side, it thinner glass negative E to the desired point being understood that when one head 51 is for making pressure contact With the press in use, the other will be shut off by any suitplate. Incidentally, in Figure 4, it will be able valve arrangement.

noted that the negative E has a square edge In carrying out my invention, the level of and that the clamping plate proper 32 is the surface of the gap frame will be slightly reversed to meet this condition. below the normal level of the rubber sealing In order to provide a seal between the two strip 22 when the latter is free from pressure. holders A and B in any relative adjusted The negative D, carried by the holder B,.will

' level of the holder the following arrangebe adjusted so as to bring the printing surment is 7 preferably employed. Around all face thereof flush with the surface of the gap four of the inner vertical surfaces 29 of the frame. When the negative holder assembly holder B is applied a flexible flap 42 which is placed in contact with the press plate and may be of rubberized cloth and of suflicient the vacuum turned on, it is evident that air width so that it will always overlap the verwill be exhausted from between the press plate .tical edge 21 of the main plate 20 in any and negative holder assembly, thus inducing adjusted position of the holder B. Backing compression of the rubber sealing strip 22, the flap 42 is a strip 43 preferably of sponge until the printing surface of the negative is in rubber and approximately of coextensive intimate contact with the sensitized surface 85. width, the rubber also extending around all of the press plate, whereupon the exposure four inner edges, as will be understood. The may be made. The air seal will be maintained flap 42 and rubber strip 43 are secured to the between the press plate and the holder asholder B preferably by relatively narrow sembly by the rubber strip 22. Between the metal plates 44 and screws 45. In actual negative and the holder B, the seal Wlll be practice, when the air is drawn out of the maintained by the rubber strip 36 and between negative holder, as hereinafter explained, the holders B and A by the flap 42 and rubber the flap 42 will be drawn against the main strip 43. plate 20 which action is, of course, augmented Referring next to the oonstructlon illusby the rubber backing strip 43 and hence trated in Figures 9, 10 and 11, the arrangea slidably adjustable seal is always mainment of main holder A and negative holder tained between the holder B and the main proper B and the sealing means associated holder A, under all operating conditions. therewith, is the same. In order to permit Due to the fact that there is always necesthe-use of flexible film negatives such as shown sarily a considerable gap between the edges at I employ n x ry holder Th o the negative and the sealing strip 22 of the latter comprises an open rectangular frame main holder A, it is essential to bridge this pref rably built p y p qy an upper gap so far as possible, in order that the press relatively wide plate 53, a similar lower plate plate, when the vacuum is on, will not be 54 and a vertical edge plate 55. TlllS frame drawn in or buckled, and hence destroy reg- F is secured. to the holder proper B by the ister and cause imperfect prints. For this same clamps'previously described for holdpurpose I employ the level guide or gap ing'glassnegatives, one ofthe clamping plates frame shown in detail -in Figures 7 and 8 proper 32 being shown in Figure 10 and sun and in section in Figure 3. Preferably, thisilarly, a seal is provided between said aux1lframe, which is detachable and removable iary frame F and the frame B by the same from the main frame A, is composed of a recrubber strip 36. When employing the auxiltangular'frame of wood 46 of suitable height iary holder F, the holder 13' will be disposed in and to the upper surface of which is applied its lowermost position with reference to the a metal plate 47, wood being'employed in main holder A, as shown in Figure 10, and

order to provideaslight amount of resiliency the seal between the two holders B and A should there be any variation in the levels is obtained by the same flap arrangement of the gap frame and the negative. The 42 and rubber strip 43. gap frame is suitably recessed as indicated at At relatively closely spaced intervals 48-48 to accommodate the clamps and operaround the outer edges of the auxiliary frame ating means therefor, as clearly shown in the F, are provided combined clamplng and drawings. To hold the gap frame in proper stretching jaws, each of which includes a position and prevent its accidental disen-' block 56 .slidably mounted within the changagement, I employ at diagonally disposed nel frame heretofore descr bedand a clampcorners thereof, spring dowel pins 49 seing jaw proper 57. The aw 57 and block cured to the main frame A and adapted to 56 have cooperable wedge-shaped surfaces 58 enter corresponding dowel openings 50 in the adapted to engage and secure the edge of wood section of the gap frame G. the film therebetween, this result being ob- When the assembledholder is on the phototained by two clamp screws 59 59. Prefergraphic printing-machine, it will be connectably, c011 springs 6060 are interposed beed with a vacuum pump, preferably through tween the jaw 57 and block 56, in order to induce separation thereof when the clamp v v dent that ing application Serial No. 729,27 7 filed on or about July 31, 1924'.

. indicated is with reference to the rubber sponge or t Very frequently flexible film negatives of a er will be employed, particularly in large work such as poster work, which paper lm may not be entirely leakproof'. To overcome any possibility of leakage through the film, I employ a film 90 entirely bridging thelight opening and the edges of which are secure to the inner edges defining the opening of the film frame F by plates 91. Said film 90 will preferably be of celluloid, of suflicient thickmess ,to provide a suitable backing for the negative film proper but thin enough to prevent interference with the transmission of light rays. If desired, a rubber strip 92 may be placed on the top surface of the film frame F beneath the negative film proper so as to further insure againstleakage when the vacuum is on.

Referring to Figures 12 and the modification shown in 13, the only difference there main holder, which, in thisinstance, is provided with its own gap or bridging means.

As shown, the main holder has a main plate 120, an outer vertically extending plate 124 and an inner vertically extending plate 146. Secured to the upper surfaces of the plates 124 and 146 is a horizontal plate 7 O which is suitably notched as indicated at 7171 to accommodate the negative clamping jaws, said plate also being provided with a series of openings or perforations 72-7 2 on all four sides, which communicate with a rectangular channel or chamber 73 formed by the plates 20, 124, 146 and 70. ,A portion of the upper surface of the plates 7 0 extending from a point outside of the perforations 72 completely to the inner edge of the plate, is deeply knurled, as indicated at 75, thereby providing a large number of air ducts, as best indicated at 173 in Figure 13, to more readily permit exhaustion of the air from beneath the negative and negative holder proper B and to positively insure exhaustion of the air throughout the entire area of contact with the press plate and thus prevent any air traps. The seal between the main holder in this construction is obtained by a flap of rubberized cloth, or the like 74, which is backed by a strip of he like 76, the flap and sponge being secured to the plate 124 by a narrow plate 77, as clearly shown in Figure compensate for variable 13. In this construction only one vacuum f head 78 is indicated, which is adapted to be connected with a suitable vacuum pump, as will be understood. I

With the construction just described, it is evident that separate gaps or bridging frames are rendered unnecessary and to accommo date different size negatives, a series of corre sponding different size main holders will be employed. Preferably, these main holders will be made principally of aluminum to lessen the weight and to facilitate handling.

I claim:

'1. In a negative holder for photographic printing machines, the combination with a main holder having air sealing means adapted to engage a print-receiving surface; of'a negative holder proper; means for retaining the two holders in predetermined assembled' relation; and air sealing means directly effective between said two holders.

2. In a negative holder for photographic printing machines, the combination with a main holder having air sealing means adapted to engage a print-receiving surface; of a negative -holder proper; adjustable means operative between the two holders for retaining them in relative predetermined position and location and at different levels to thickness of negatives; and air sealing means directly effective between the two holders.

3. In a negative holder for photographic printing machines, main holder having means adapted to provide an air seal with a print-receiving surface; of a negative holder proper; means providing an air seal between said holder the combination with a and means carried by one of said holders co- 3 operable with the other holder to provide an air seal between the two holders.

4. In a negative holder for photographic printing machines, the combination with a main holder having air sealing means cooperable with a print-receiving surface; of a negative holder proper; adjustable means for retaining the negative holder proper at different levels with respect to the main holder; and air sealing means carried by one of the holders and adjustably engaging the other of 'said holders.

5. In a negative holder for photographic printing machines, the combination with a main vacuum frame holder having air sealing means cooperable with an opposed printreceiving surface; a negative holder proper disposed within the confines of and of lesser area than said vacuum frame holder whereby gaps are left between the negative and said sealing means; and means disposed within said gaps and substantially flush with the negative surface whereby to prevent displacement of the print-receivingsurface within said gaps when the vacuum is on.

6. Ina negative holder for photographic printing machines, the combination with a main vacuum frame holder having air sealing means cooperable with an opposed printreceiving surface; a negative holder proper disposed within the confines of and of lesser area than said vacuum frame holder whereby gaps are left between the negative and said sealing means; and a removable frame disposed within said gaps and having its upper surface substantially flush with the negative surface whereby to prevent dis placement of the print-receiving surface within said gaps when the vacuum is on.

7. In a negative holder for photographic printing machines, the combination with a main vacuum frame holder having air seal ing means cooperable with an opposed printreceiving surface; a negative holder proper disposed within the confines of and of lesser area than said vacuum frame holder whereby gaps are left between the negative and said sealing means; a detachable gap-bridging frame surrounding the negative holder proper; and means for retaining said gapbridging frame assembled with the main holder.

8. In a negative holder for photographic printing machines, the combination with a main holder having a central opening and provided with means adapted to form an air seal with an opposed print-receiving surface; a negative holder having a central opening in register with said first named central opening; means for adjusting the level of the negative holder with reference to the main holder; and means providing an air seal between said two holders.

9. In a negative holder for photographic printing machines, the combination with a main holder having a central opening and provided with means adapted to form an air seal with an opposed print-receiving surface; a negative holder having a central opening in register with said first named central opening; means for adjusting the level of the negative holder with reference to the main holder; means for accurately predetermining the position and location of the negative A holder with reference to the main holder; and

adjustable means providing an air seal between the two holders at any level of the negative holder with reference to the main holder.

10. In a negative holder for photographic printing machines, the combination with a main holder; of a negative holder; and means providing an air seal between said holders, said means including a flexible flap bridging the gap between the two holders and a resilient backing for said flap.

11. In a negative holder for photographic printing machines, the combination with a main holder having a central opening defined by vertical edges of the main holder; of a negative h'older having a central opening defined by vertical edges thereof and of the same size and contour as the opening in the main holder; means for adjusting the level of the negative holder with reference to the main holder; and means for sealing the joint between the two holders along their vertical edges defining the openings, said means including a flexible flap secured to one of said holders and extending loosely over the joints.

12. In a negative holder for photographic printing machines, the combination with a rectangular main holder having a central rectangular opening, a flat bottom plate and. air sealing means extending around the periphery on one side thereof; of a negative holder proper of rectangular form and having a central rectangular opening in register with the opening of the main holder, said negative holder proper having a plurality of adjustable clamping jaws around the periphery thereof; adjustable means for varying the level of the negative holder proper with reference to the main holder; air sealing means between the two holders effective in any relative adjusted position of the negative holder; and cooperating means between the two holders for positioning and locating the negative holder proper with reference to the main holder in a predetermined position and location.

13. In a negative holder for photographic printing machines, the combination with a rectangular main holder having a central rectangular opening, a fiat bottom plate and air sealing means extending around the periphery on one side thereof; of a negative holder proper of rectangular form and having a central rectangular opening in register with the opening of the main holder, said negative holder proper having a plurality of adjustable clamping jaws around the periphery thereof; adjustable means for varying the level of the negative holder proper with reference to the main holder; .air sealing means between the two holders effective in any relative adjusted position of the negative holder;

cooperating means between the two holders.

for positioning and locating the negative holder proper with reference to the main holder in a predetermined position and location; and a removable gap frame supported i on the main holder and disposed around the periphery of the negative holder proper.

14. In a negative holder for photographic printing machines, the combination with a rectangular main holder having'a central rectangular opening, a flat bottom plate and air sealing means extending around the periphery on one side thereof; of a negative-holder proper of rectangular form and having a central rectangular opening in register with the opening of the main holder, said negative holder proper having a plurality of adjustable clamping jaws around the periphery,

thereof adjustable means for varying the level of the negative holder proper with reference to the main holder; air sealing means between the two holders effective in an relative adjusted position of the negative holder; cooperating means between the two holders for positioning and locating the negative holder proper with reference to the main holder in a predetermined position and location; and a removable gap frame supported on the main holder and disposed around the periphery of the negative holder proper, said gap frame being provided with recesses to accommodate the clamping jaws of the negative holder proper.

In witness that I claim the foregoing I have hereunto subscribed my name this 18th day of July, 1928.

.WILLIAM C. HUEBNER. 

